Yes. Given that they are smaller than the typical 3.5-inch sized business card, square cards can fit nicely into a wallet. And not only that, square business cards fit inside a fob pocket (the small pocket in your jeans), or in a shirt pocket.
But don’t think that the smaller size means it is less memorable. As a matter of fact, square business cards tend to stand out more. For one, they have a different shape so they are more interesting to look at. Also, as they are smaller, they usually feature simple but vibrant designs.
Square business cards are versatile, unique, and look very much in the now.